No SU Binary Installed?

Hi guys! I'm pretty much a noob when it comes to rooting and stuff, so please help me out >_< !
I tried to disable SuperUser and denied accesses of the apps that SuperUser had granted permission to (in order to play Avabel, but I couldn't anyway </3 ). Then I restarted the phone and found out that I couldn't enable SuperUser. This is what the app said: https://www.dropbox.com/s/k90zeehdbzm2jff/2014-09-15 10.54.14.png?dl=0
I tried to install Mobile Odin to fix the problem, but it said "SuperUser access is needed, but could not be acquired." (I downloaded an APK of Odin if that matters :/ ). I couldn't uninstall SuperUser either. And my phone is a Galaxy S5, and Android version is 4.4.2.
Thanks ahead for your time!